X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 25 May 2011 07:41:09 -0400 Message-ID: X-Original-Return-Path: Received: from nm11-vm0.bullet.mail.sp2.yahoo.com ([98.139.91.240] verified) by logan.com (CommuniGate Pro SMTP 5.4c3j) with SMTP id 4993473 for lml@lancaironline.net; Tue, 24 May 2011 20:19:01 -0400 Received-SPF: none receiver=logan.com; client-ip=98.139.91.240; envelope-from=n20087@yahoo.com Received: from [98.139.91.69] by nm11.bullet.mail.sp2.yahoo.com with NNFMP; 25 May 2011 00:18:27 -0000 Received: from [98.139.91.5] by tm9.bullet.mail.sp2.yahoo.com with NNFMP; 25 May 2011 00:18:27 -0000 Received: from [127.0.0.1] by omp1005.mail.sp2.yahoo.com with NNFMP; 25 May 2011 00:18:27 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 908586.59096.bm@omp1005.mail.sp2.yahoo.com Received: (qmail 92146 invoked by uid 60001); 25 May 2011 00:18:27 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=GnFDACuHkLfWkuDJPrDrx+v2Qpo2kxPZ/VKwphPpebfdHjAfA35pI20m2pFwIZRvHAeIDvfYidM8Ih4rhzijA0yDsKju6wPKnOouGAt8Jj+Khgq9fQCjlTokzxH+ICxVkzw+r+0fMjD1ITfPUKM9zpNk3xI63iSifvYw2cvBopM=; X-Original-Message-ID: <615764.90777.qm@web112701.mail.gq1.yahoo.com> X-YMail-OSG: H3YYzrwVM1mtjNXmP6oyDuJFmR3gAc6kiiRSMYXBAoPfGMZ u1KgQv5xlPxUVeH.Uyd6XskijSrOgZZgdiGllTMrY1NLx2yzAn86RkyyAb9S 8bJKuWEcTvBVLzqpCWJwKOaumHJvw1zlvoE5KxKDGPFyGXjrczB21sRpBQRQ 6cu.hny9_z_KX3eX.bYjB0fn43X7mcjFMjCD.Yp2gswFd0XbbM0RICIYjKu8 nDKDheOLAvZEZXNzgOXUhjdDNi8mEX5HgoN87_oy87fqNx.T0DKPSD2AwWyv 4sVmIoOpyVwMaEEq_T7ib9HftVnwgvdwE5TqXah76B9doxtsTMCxKwWRzWoj tdQ1.Exn4387pB06HWCm9v6PLjyn9xhnwFW70djcOIH9o_DyVup8JZ5Q- Received: from [98.185.51.168] by web112701.mail.gq1.yahoo.com via HTTP; Tue, 24 May 2011 17:18:27 PDT X-Mailer: YahooMailRC/567 YahooMailWebService/0.8.111.303096 References: X-Original-Date: Tue, 24 May 2011 17:18:27 -0700 (PDT) From: TOM GARDINER Subject: Re: [LML] Fuel restriction or air part 2 X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1963104735-1306282707=:90777" --0-1963104735-1306282707=:90777 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Berni,=0A=0AI am seeing the same symptoms on my aircraft under the same cir= cumstances but =0Awithout the engine surging.=A0 The fluctuations only last= a few seconds before =0Anormal pressure and flow is restored.=A0 Turning o= n the boost pump briefly will =0Aclear the symtoms but the issue will retur= n after a few minutes.=A0 My theory is =0Athat the fuel is vaporizing in th= e engine driven pump.=A0 My crossover exhaust =0Aruns under the pump and is= seperated by about 5 inches.=A0 I am thinking radiation =0Aheating=A0from = the exhaust is the culprit.=A0 My plan is to put heat shields on the =0Apip= es and=A0run an air blast=A0to the pump.=A0 I wll let you know how this wor= ks out=0A=0ATom=0A=0ALNC2=A051 hrs=A0=A0=0A=0A=0A=0A=0A____________________= ____________=0AFrom: Berni =0ATo: lml@lancaironline.ne= t=0ASent: Tue, May 24, 2011 12:23:21 PM=0ASubject: [LML] Fuel restriction o= r air part 2=0A=0AFirst of all...thanks to everyone that has tried to help = me with my engine surge =0A(fuel related) problem on my normally aspirated = Lancair IV.=A0 I have throughly =0Achecked and tested everything suggested = so far.=A0 There are no tank vent issues =0Aand a vacuum test of the entire= system from the engine driven fuel pump back to =0Athe tanks proved there = is no air getting into the system.=A0 I even replaced the o =0Arings on the= inlet and outlet sides of the electric fuel pump just to be sure.=A0 =0AUn= fortunately my test flight this morning confirmed that the issue still =0Ar= emains.=0A=0AThis is what happened.=A0 On a 50 mile cross country where I t= ook off and climbed =0Ato 7,500 I experienced zero issues.=A0 I landed took= on some fuel and took off for =0Ahome.=A0 I climbed to 7,500 again and saw= that the fuel flow and fuel pressure =0Agauges were fluctuating.=A0 Since = this occurrence preferred my engine surge =0Aproblem in the past I knew it = was coming and it did.=A0 The engine began surging =0Aand continued to do s= o until I turned on the electric ( back up) fuel pump.=A0 The =0Aengine and= gauge readings stabilized immediately.=0A=0ASo this is where I am...I know= I do not have any vacuum (air) leaks from the =0Atanks through to the engi= ne driven pump, nor do I have any restrictions in the =0Afuel lines or fuel= tank vents.=A0 I have replaced my engine driven pump.=A0 All =0Asymptoms r= emain.=0A=0AQuestion...if I am at cruise settings and leaned out reading 16= GPH on the fuel =0Aflow and 10PSI on the fuel pressure should this readings= rise when I turn the =0Aelectric fuel pump on?=A0 My GPH goes from 16 to 2= 1 and my fuel pressure goes from =0A10 to 15 or higher.=0A=0ASent from my i= Pad=0ABerni Breen=0ABbreen@cableone.net=0A--=0AFor archives and unsub http:= //mail.lancaironline.net:81/lists/lml/List.html=0A --0-1963104735-1306282707=:90777 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Berni,
=0A
 
=0A
I am seeing the same sympt= oms on my aircraft under the same circumstances but without the engine surg= ing.  The fluctuations only last a few seconds before normal pressure = and flow is restored.  Turning on the boost pump briefly will clear th= e symtoms but the issue will return after a few minutes.  My theory is= that the fuel is vaporizing in the engine driven pump.  My crossover = exhaust runs under the pump and is seperated by about 5 inches.  I am = thinking radiation heating from the exhaust is the culprit.  My p= lan is to put heat shields on the pipes and run an air blast to t= he pump.  I wll let you know how this works out
=0A
 =0A
Tom
=0A
 
=0A
LNC2 51 hrs  = ;
=0A

=0A
=0A
=0AFrom: Berni <bbreen@cableone.net&= gt;
To: lml@lancaironlin= e.net
Sent: Tue, May 24,= 2011 12:23:21 PM
Subject: [LML] Fuel restriction or air part 2

First of all...thanks= to everyone that has tried to help me with my engine surge (fuel related) = problem on my normally aspirated Lancair IV.  I have throughly checked= and tested everything suggested so far.  There are no tank vent issue= s and a vacuum test of the entire system from the engine driven fuel pump b= ack to the tanks proved there is no air getting into the system.  I ev= en replaced the o rings on the inlet and outlet sides of the electric fuel = pump just to be sure.  Unfortunately my test flight this morning confi= rmed that the issue still remains.

This is what happened.  On a 50 mile cross country where I took off and climbed to= 7,500 I experienced zero issues.  I landed took on some fuel and took= off for home.  I climbed to 7,500 again and saw that the fuel flow an= d fuel pressure gauges were fluctuating.  Since this occurrence prefer= red my engine surge problem in the past I knew it was coming and it did.&nb= sp; The engine began surging and continued to do so until I turned on the e= lectric ( back up) fuel pump.  The engine and gauge readings stabilize= d immediately.

So this is where I am...I know I do not have any vacu= um (air) leaks from the tanks through to the engine driven pump, nor do I h= ave any restrictions in the fuel lines or fuel tank vents.  I have rep= laced my engine driven pump.  All symptoms remain.

Question...i= f I am at cruise settings and leaned out reading 16GPH on the fuel flow and= 10PSI on the fuel pressure should this readings rise when I turn the electric fuel pump on?  My GPH goes from 16 to 21 and my fuel pre= ssure goes from 10 to 15 or higher.

Sent from my iPad
Berni Breen=
Bbreen@cableone.net
--
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